This was the code used to drive the heart of our piece. The project was part of the robotics for Creative Pratice course at Carnegie mellon.
The code was built on top of the StepperWinch Program developed by Garth Zeglin. That code can be found in the link below https://courses.ideate.cmu.edu/16-376/s2020/ref/text/software/StepperWinch.html
In essence, this is a Zeotrope that starts and changes color based on the input of two different ultrasound sensors.
You can find the youtube Videos showing the progressive build of the piece in the link below. https://youtube.com/playlist?list=PLgK8ktcGDGs_JM1s6qz76z2ol__JUwTJW
Final Video trailer https://youtu.be/fU3-fOXpoGg
The final Documentation on the Piece can be found in the link below https://courses.ideate.cmu.edu/16-375/f2021/work/2021/12/02/who-are-you/
Below are the daily notes taken into account as this project was developed.
We want to modify the ultrasound sensor to use SPindle Direction and enable now we would also like to have this not use a delay.
https://roboticsbackend.com/arduino-pulsein-with-interrupts/
We need to measure the high end of the echo pin
https://www.arduino.cc/en/Reference.PulseIn
So for the arduino uno only pin 2 and 3 can have an interrupt attached to them
that is why we are using the y step
we need have the echo be on something to detect 40 cm or less
1 microseconds would detect 20 cm
We got most of this to work with the RGB The light isn't as strong
We can set the color to whatever we like by using the code color R G B where each value is from 0 to 255
Now we need to setup the Ultrasound Sensors We have two ultra sound sensors https://create.arduino.cc/projecthub/abdularbi17/ultrasonic-sensor-hc-sr04-with-arduino-tutorial-327ff6
Supply voltage needs to be 5V. There is GND and Triger and echo They didn't work with A4 and A5
it does work with digital pins. We need to turn it on when value is less than 20 cm
Both Ultrasound sensors seem to work in this scenario
A reading will take 12 microseconds We can do a reading every second and the system seems to work fine
Let's try to see if we can get the on and off system to work.
SDA And SCL can be for the first ultrasound We can do a check every 5 seconds if someone is less than 10 cm away
This will cause the zeotrope to turn on and off respectively.
The pulse in function is blocking so we need to add timer interrupt on the system to read the value First need to check if this works. For the turn on and turn off. We can shorten the delay and that wouldn't cause to many issues for the delay in and out.
You need to stay looking at it for 5 seconds. if the user steps away it will stay on for 50 seconds
This is an absolute move. a x 50 move the X axis to +50 this would move it to a +50 location
d x 50 would just move x 50 plus
There seems to be some oscillation. We might need to improve the PIDs here.
set all channels to 0.1 Hz natural frequency and underdamping g xyza 0.1 0.5
This seems to work g xyza 0.1 1
is the best result at 200 micro steps. g xyza 0.5 1
We have 12 figures. We want the strobe to flash at certain marks We need to mod 200 what ever position we need to have it to strobe on the 16.666 mark
we have 360 degrees per revolution. in 200 counts that would be 1.8 degree per count.
Each of the slots is 10 degrees. how many counts would that be.? 10/1.8= 5.555 steps It's more like 5 degrees per slot. 5/1.8= 3 So we need 3 micro steps or smaller to flash 5*12 would mean 60 degrees are covered by slots. 60/360 that would mean something like 16 percent of the circle. which is like 3 steps of 16.66 which is around 18 percent.
We might need to use smaller micro steps https://courses.ideate.cmu.edu/16-375/f2021/text/hardware/cnc-shield.html#id17
Micro stepping suggests that we need to be to remove the things below the driver We are now setting this to eighth step.
2X, 4X, 8X, or 16X the full-step resolution
The stepper motor runs at KL17H248-15-4A NEMA17 stepper motor with the CNC Shield. This is a bipolar 200 counts/rev
So we had 3200 micro steps at 16x
We are using driver x v x
We removed M2 which caused an eighth step. 200 * 8 1600 per revolution
No pins attached makes this a full step revolution So 200 steps per revolution
We have 6 figures on the zeotrope. if we want to do 12 frames a second. We need to do 2 revolutions per second. The time period for 12 Hz is
The strobe light was set to a 50/50 duty cycle.
We need to shorten that duty cycle
So we need to set the interval between these two to get a better desired effect.
We might need to shorten our test phase and see how we can get there faster.